Prognostic value of systemic immune-inflammation index in cervical cancer: a systematic review and meta-analysis.

[BACKGROUND] A growing body of evidence indicates that the systemic immune-inflammation index (SII) is associated with the prognosis of cervical cancer (CC). However, its prognostic value remains controversial. This study aimed to comprehensively evaluate the performance of SII in predicting the prognosis of CC.

[METHODS] Studies on the prognostic potential of SII in CC were acquired from PubMed, Embase, Web of Science, and the Cochrane Library from database inception to July 4, 2024. Outcome measures included progression-free survival (PFS), overall survival (OS), relapse-free survival (RFS), and complete response (CR), which were expressed as hazard ratio (HR) and 95% confidence interval (CI). Sensitivity and subgroup analyses were carried out to evaluate the stability of results and identify potential sources of heterogeneity.

[RESULTS] Ten cohort studies involving 2007 patients were included in the meta-analysis. High SII levels were significantly associated with reduced OS (HR = 2.45; 95% CI: 1.56-3.86,  = 0.001), PFS (HR = 2.93; 95% CI: 1.88-4.58,  < 0.00001), and CR (HR = 0.23, 95% CI: 0.11-0.50;  = 0.0002) in patients with CC. Subgroup analyses suggested that SII was more effective in predicting outcomes in Asian patients with CC.

[CONCLUSIONS] High SII levels are significantly associated with reduced OS, PFS, and CR in CC. Therefore, SII is a promising biomarker for predicting outcomes and informing treatment decisions for immunotherapy in CC.